Combined injection and blending apparatus



I w. P. DOOLEY COMBINED INJECTION AND BLENDING APPARATUS Fil ed Dec. 27,1954 July 9, 1957 2 Sheets-Sheet 1 an \N July 9, 1957 w. P. DOOLE'Y2,798,698

COMBINED INJECTION AND BLENDING APPARATUS I Filed Dec. 27', 1954 2Sheets-Sheet 2 United States Patent C) COMBINED INJECTION AND BLENDINGAPPARATUS William P. Dooley, South Charleston, W. Va., assignor toAmerican Viscose Corporation, Philadelphia, Pa., a corporation ofDelaware Application December 27, 1954, Serial No. 477,904

9 Claims. (Cl. 259-9) This invention relates to liquid injection andblending apparatus, and more particularly to a device for injecting asecondary stream of viscose into a primary stream of viscose.

The problems connected with the injection of one stream of a liquid suchas viscose into a second viscose stream are, to a considerable extent,influenced by the nature of the liquid itself. Such problems have to dowith the elimination of dead spots where the viscose may become stagnantor may have a tendency to set up. In addition the viscous nature of thefluid may cause a considerable pressure drop through the blendingapparatus. This condition is highly undesirable since it requires one ormore booster pumps in the line. The very nature of viscose is such thatthe injected stream tends to resist complete mixing and thereforerelatively violent agitation and blending is required to achievehomogeneity.

A primary object of the invention therefore is to provide a combinedinjection apparatus and blender which is highly eflicient in itsblending characteristics and which at the same time eliminates pressuredrop through the blender.

A further object of the invention is to provide a combined injectionblender for viscous liquids which is selfcleaning.

A still further object of the invention is to provide an improvedinjection blender having no stagnant areas.

A still further object of the invention is to provide an improvedinjection blender having a two-stage blending element mounted on acommon shaft, the first stage comprising a high speed agitator ofrelatively small diameter and the second stage comprising a series ofrotors and stators of relatively larger diameter.

A still further object of the invention is to provide a combinedinjection blender for viscose in which one of the rotor elements acts asa centrifugal pump to offset pressure drop in the device.

Further objects will be apparent from the specification and drawings inwhich:

Figure 1 is a longitudinal sectional view through a combined injectionblender constructed in accordance with the present invention;

Figure 2 is an enlarged sectional view showing the injection device usedin the construction of Figure 1;

Figure 3 is a perspective of one of the rotor elements; and

Figure 4 is a longitudinal sectional view of a modified form of combinedinjection blender.

The invention comprises essentially the provision of a primary fluidhousing having a plurality of alternating stator and rotor elementstherein. The rotor shaft is provided with a preliminary agitatingelement which initially directs the secondary stream in all directionsthrough a preliminary mixing chamber. The secondary stream is deliveredto a zone immediately in front of and in line with the axis of thepreliminary agitator. In one form of the apparatus, the primary flowtakes place axially through the rotor and stator elements and in another form the last rotor discharges the mixed primary and secondaryliquids tangentially through a discharge port at right angles to theaxis of the rotor shaft.

Referring now more particularly to the drawings, the apparatus shown inFigures 1-3 comprises a housing 10 having a relatively large circularbore. The intake end of housing 10 is connected to the intake elbow 11by means of a flanged connection 12 having a suitable gasket 13. Theoutlet end of housing 10 connects to curved outlet elbow 14 throughflanged connection 15 having gasket 16. The blending or mixing structureis completely contained in housing 10 and comprises a rotor shaft 17which extends through elbow 14 and is journaled in outboard bearingassembly 18 and inboard bushing 19. A stufling box 20 is providedbetween the bearing assembly 18 and the elbow 14 as shown in Figure l.The extreme end of shaft 17 carries a high speed agitating element 21having a hollow construction with a fluid shearing surface 22. Thiselement is well known as an independent mixing device and forms no partof the present invention apart from its combination with the remainingstructure. The discharge end of housing 10 is counterbored to receive insequence the first stator element 25 which carries the bushing 19; thenext stator element 26 which is of slightly larger diameter, and retainsa spacing collar 27; and the third stator element 28 of still largerdiameter which in turn retains a spacing collar 29. All of the statorsand collars are held in position by the flanged connection 15. Eachstator contains a series of perforations preferably arranged inconcentric rows to permit passage of the liquid and to break up theinitially mixed streams into relatively fine streams. Shaft 17 carriestwo rotors 30 and 31 which in the present instance are of identicalconstruction as shown in Figure 3. Each rotor has a solid hub that iskeyed to shaft 17 by set screws 32, 32 and the periphery of the rotorscomprises a plurality of spokes 33, 33 having a substantiallyrectangular cross section. In addition to the spokes, I provide threesets of vanes 34, 34 which act as shear elements to vigorously break upand mix the individual streams delivered through the perforations of thestators. As shown in Figure l, the first rotor 30 is positioned betweenstators 25 and 26 whereas the second rotor 31 is positioned betweenstators 26 and 28.

The primary liquid stream such as viscose is delivered to housing 10through inlet 11. The secondary liquid such as a delusterant or acoloring fluid is delivered through the injector assembly connected toinlet 11 so that the tip or discharge end of the injector terminates inclose axial spaced relation to the agitator 21. The injector assembly(Figure 2) comprises a housing 41 to which the secondary fluid iscarried by means of a pipe or conduit 42. A spring loaded valve 43extends axially through housing 41 and prevents backing up of theprimary fluid into housing 41 should the pressure in the housing fallbelow the pressure of the primary stream. Valve stem 43a extends throughthe gland assembly 44 and is adjustably spring loaded by means of acompressing spring 45 and nuts 46, 47. It will thus be understood thatthe primary liquid stream is delivered in an axial direction to theblending elements in housing 10 and that the secondary stream islikewise delivered in line with the primary stream to a zone directly atthe intake of the agitating element 21. This device turns at a speed ofapproximately 3500 R. P. M. so that there is vigorous preliminaryagitation in the inlet zone of chamber 10. The initially mixed streamsthen pass through the various rotor and stator stages and are dischargedaxially in a completely homogeneous state through the discharge elbow14.

A modified form of combined injection blender is shown in Figure 4 whichis particularly useful where minimum pressure drop through the blenderis indicated. In this form the housing has an inlet flanged coupling 51through which the primary stream enters the housing. The secondarystream is delivered to a point or zone directly in front of thepreliminary agitator 52 through an injector nozzle 53. However, althoughthe zone at which the secondary fluid is discharged is the same as thatshown in Figure 1 in the modified form, the secondary fluid entershousing 50 from the side through a boss 54 rather than in an axialdirection. The blending stages in the form of Figure 4 comprise thefirst stator 55 separated from the second stator 56 by means of a collar57. This form has only two stators, however, and the shaft 58 is notjournaled in either of the stators. The first rotor 59 is positionedbetween stators 55 and 56, and the second rotor 60 is in line with thedischarge fitting 61 at right angles to the axis of the rotors andshaft. In this way it will be seen that the rotor 60 functions inaddition to its mixing action as a centrifugal pump to boost thedischarge pressure from the blender and thus eliminate the necessity forinstalling a secondary booster pump in the line should the pressure dropbe considered excessive. This tangential rather than axial outlet alsopermits the entire shaft and rotor assembly to be carried in veryadequate outboard supports.

The flange joint assembly 65 comprises an intermediate cap 66 for thehousing 50 which is provided with a bushing 67 that may be lubricated bythe viscose or liquid in chamber 50. The bearing housing 68 is alsosupported at the flange assembly 65 by the connecting bolts 69, 69.Annular ball bearing assemblies 70, 70 are positioned in axial spacedrelation in housing 68 to carry the radial loads imposed by the weightof the agitator 52 and the rotors 59 and 60. The inner cap 71 having alubricant seal 72 is secured to the housing 68 by cap screws 73, 73, andthe outer cap 74 having a lubricant seal 75 is connected to the housing68 by cap screws 76, 76. Lubricant is introduced to the enlarged bore ofthe housing and thence to the bearings 70 through a grease fitting 77.The inboard bearing is retained on shaft 58 by means of a nut 78 andlock washer 79.

The combined injection blender, as described above, is admirably suitedfor use with relatively thick viscous liquids such as viscose. It issimple, effective and the two stages provide exceptionally effectiveblending for the addition of any desired secondary fluid which may be anadditive intended to accomplish an improved physical characteristic inthe extruded filaments, a delusterant or a pigmented mixture forcoloring purposes only. r

Depending upon the particular installation, the design may be modifiedto operate as a booster pump if the elimination of pressure drop throughthe device is important. Low cost, adequate capacity and elimination ofstagnant areas together with very complete blending are importantfeatures of the design.

Having thus described my invention, I claim:

1. A combined injection blender comprising a housing, means foradmitting a first liquid to one end of said housing, a first-stagerotary agitator in said housing being of substantially smaller diameterthan the bore of the housing, a second-stage agitator in said housing,said secondstage agitator comprising a plurality of rotors andinterspersed stators of substantially the same diameter as the bore ofthe housing, a common shaft on which said first and second-stageagitators are mounted, and a secondary injection nozzle terminating inclose axial spaced relation to the first-stage agitator at a pointbetween said agitator and said first liquid injection means.

2. Apparatus in accordance with claim 1 in which the shaft is partiallyjournaled in one of the stators.

3. Apparatus in accordance with claim 1 in which the shaft is cantileverjournaled exteriorly of the housing.

4. Apparatus in accordance with claim 1 in which the injection nozzleenters the housing concentrically and axially to the shaft.

5. Apparatus in accordance with claim 1 in which the injector nozzleenters the housing at right angles to the centerline of the shaft.

6. Apparatus in accordance with claim 1 in which the housing has adischarge conduit extending in an axial direction therefrom.

7. Apparatus in accordance with claim 1 in which the housing has atangential discharge conduit in line with one of the rotors.

8. Apparatus in accordance with claim 1 in which the rotors haveperipheral spokes of rectangular cross section, and a plurality ofradially extending vanes substantially wider than the width of thespokes.

9. Apparatus of claim 1 comprising means for lubricating the shaft withthe material being blended.

References Cited in the file of this patent UNITED STATES PATENTS338,121 Wallace Mar. 16, 1886 1,948,871 Quehl Feb. 27, 1934 2,146,776Strominger Feb. 14, 1939 2,240,841 Flynn May 6, 1941 2,287,067 SchmidtJune 23, 1942

